//
// Copyright (c) 2010 Luís Reis
//
// MIT License
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
using System;
namespace Pine.Core
{
	public class NullValue : Value
	{
		public static readonly NullValue Null = new NullValue();
		private Function ToStringWrapper;
		
		private NullValue() {
			ToStringWrapper = new Function(null, ToStringAdapted);
		}
		
		private void ToStringAdapted(Function f, ValueList rl) {
			rl.Clear();
			rl.SetArrayElement(new Number(0), new StringValue("null"));
		}
		
		public override Value GetPineType() {
			return Null;
		}
		
		public override bool ToBoolean ()
		{
			return false;
		}
		
		public override string ToString ()
		{
			return "null";
		}
		
		public override Value FieldGet (string fieldname)
		{
			if (fieldname == "toString")
				return ToStringWrapper;
			return base.FieldGet (fieldname);
		}
	}
}

